Electric welding apparatus



p 9 1949- B H. LEPINE-WHLLIAMS 2,481,317

ELECTRIC WELDING APPARATUS Filed Aug. 21, 1947 Patented Sept. 6, 1949 ELECTRIC WELDING APPARATUS Basil Heathcote Lepine-Williams,

Coventry, England Application August 21, 1947, Serial No. 7 69,926 In Great Britain September 16, 1946 1 This invention relates to electric welding apparatus and has for its object to provide an improved form of apparatus particularly suitable for the welding of aluminium and other li alloys although it will be understood that the invention is not restricted in this respect.

The invention consists in electric welding aparatus comprising a fixed head to support a first electrode, a movable table to support a second electrode, means for moving the said movable table to and from the said fixed head to make contact between the said first and second electrodes and to complete the welding cycle, movable clamping means upon the fixed head to secure the said first electrode thereupon, movable clamping means upon the movable table to secure the said second electrode thereupon, a delay device including control means associated with th means for moving the said movable table and the means for moving the movable clamping means, adjustable means fixed upon the fixed head and movable table operated by movement of one member towards the other to initiate the delayed cycle of operation including the releasing of the clamps and movement of the table away from the fixed head and manually operable means for con trolling the closing of the clamps and movement of the table towards the fixed head.

Further features of the invention will be apparent from the description given hereafter.

The accompanying drawing illustrates more or less diagrammatically one convenient form of apparatus in accordance with the invention.

In carrying my invention into efiect in one convenient manner I form my improved welding apparatus with two clamps for holding the electrodes a and b, one being arranged on a fixed head e, while the other is mounted on a movable table I. The operation of the clamps and of the table is conveniently efiected by air or other fluid under pressure and in association with the apparatus I provide a limit switch 2' adapted to be actuated automatically by the movable head and table through adjusting screw 7' in order that the position of the table at which the limit switch operates can be varied. When the table is moved to bring the clamps together limit switch 2' opcrates to close an electronic or other suitable timing circuit is, which after a predetermined period of delay (which may be varied to suit the nature of the welding operation to be performed) trips contactors energising electromagnetically operated valves 1, m controlling the supply of fluid to and from the cylinders g, h to open the clamps and initiates a timing circuit which ener- 2 Claims. (Cl. 219-4) gises an electromagnetically operated valve s controlling the supply of pressure fluid to the return cylinder on the table or movable head to return same to the normal position for the next weld.

The supply of welding current may be provided by a transformer 11. across the secondary of which the parts e, j are connected, and clamp controlling push buttons 0, p may be provided to start up the apparatus.

In operation of the machine the working pieces 0 and d are placed in the clamps which are closed by depressing push buttons 0 and 11, this completes the circuit energising th coils of the contactors, thus actuating the valves Z and m which cause a fiow of fluid to act upon the top surface of the pistons g and h, thus clamping the working pieces 10 and d. When the table I is moved forward in order to make the weld the adjustable screw 9' closes the limit switch 2' a predetermined position which is adjustable to suit the nature of the work being performed.

By way of illustration the flow of fluid in the pipes is shown at the commencement of the welding cycle.

It will be understood that the foregoing details of construction are given purely by way of example to indicate the nature of the invention and not to limit its scope and in place of the fluid pressure operated means for actuating the clamps and table I may employ electrical or mechanical means for the purpose, in which case the controls governed by the automatically operated limit switch would be chosen to suit the character of operating means employed.

I claim:

1. Electric welding apparatus comprising a fixed head to support a first electrode, a movable table to support a second electrode, means for moving the said movable table to and from the said fixed head to make contact between the said first and second electrodes and to complete the welding cycle, movable clamping means upon the fixed head to secure the said first electrode thereupon, movable clamping means upon the movable table to secure the said second electrod thereupon, a delay device including control means associated with the means for moving the said movable table and the means for moving the movable clamping means, adjustable means fixed upon the fixed head and movable table operated by movement of one member towards the other to initiate the delayed cycle of operation including the releasing of the clamps and movement of the table away from the fixed head and manually operable means for controlling the closing of the the said first; and said; second electrodes, and to;

complete-the-weldingcycle, fluid operated-clamping means upon the fixed head to secure the said first electrode thereupon, fluid operated clamping means upon the movable table t -;.secu re the;

second electrode thereupon, electromagnetically operated valves associated with the: means foil moving the table and the clamping means; an-" 5 electrical delay device for controlling tl qop era tion of said valves, adjustable meajns lupongithe;

movable table associated with means upon the fixed head to close an electric circuit by'm'ovement of the table towards the fixed head to 20 initiate a delayed cycle of operation including the release of the clamps and movement of the table away from the fixed head, the extent of the delay being adjustable to a predetermined period, and manually operable means for closing electric circuits for the closing of the clamps and movement of the table towards the fixed head.

BASIL H: LEEI'NEWFH-ZLRAMS.

REFERENCES CITED 'The following references are of record in the file -0 f: this; patent:

UNITED STATES PATENTS Number Name Date 1,847,890 Osborne Mar. 1, 1932 -1-,832,-2 0,8 Ferris et al. Dec. 2'7, 1932 1,902,955 Holmes Mar. 28, 1933 22113186 Weston Aug. 13, 1940 2,359,324 Marcaux Oct. 3, 1944 

